Regenerator



Oct. 1931. F. CREED ET AL REGENERATOR Filed Dec. 22 1928 4 Sheets-Sheet 1 is; i E

FREDERICK G. CREED REGINALD D. SALMON ATTORNEY Oct. 13, 1931. CREED 1- 1,827,460

REGENERATOR Filed Dec. 22, 1928 4 Sheets-Sheet 2 FREDERICK 'G- CREED REGINALD D-SALMON ATTORNEY Oct. '13, 1931. G CREED ET AL 1,827,460

REGENERATOR Filed Dec. 22', 1928 4 Sheets-Sheet s FREDERICK scnc zo Nvf N TOR 5 REGINALD DISH-MON o ATTORNEY W Oct 13, 1931. CREED E L 1,827,460

REGENERATOR Filed Dec. 22, 1928 4 Sheets-Sheet 4 F/ G. 8- Y W A-r-roangv Patented Oct. 13, 1931 UNITED STATES PATENT OFFICE FREDERICK GEORGE CREED AND REGINALD DENNIS SALMON, OF CROYDON, ENGLAND, ASSIGNORS TO CREED AND COMPA NY, LIMITED, OF TELEGRAPH WORKS, CROYDON,

ENGLAND nnennnanron Application flled necember 22, 1928, Serial No. 327,988, and in Great Britain December 24, 1927.

weakened. I

Various methods have been employed to reproduce the signals in their original form and thus avoid the disadvantagesdue to the reception of distorted signals. Such meth- 1o ods have not however given altogether satisfactory results in practice. The problem; of reproducing distorted signals in their or1g1- nally transmitted form, ultimately resolves itself into two portions, namely (1) to pro-' duce a telegraph receiving apparatus having a member adapted to move in synchronism and correct phase relationship with the corresponding movable member of the associated telegraph transmitting apparatus, and.

(2) to determine the character of each signal as received and to bring into action the appropriate reproducing means, utilizing for this purpose the smallest proportion possible of the signal period. The portion of the gnal period used for determining the character of the signal would naturally be the middle portion, as this is the only portion which must not be incorrect if the signal is to be reproduced correctly by any means at all, any distortion that takes place having the effect of rendering the remainder of the signal uncertain.

The present invention has for its object to provide a method of and means for maintaining a signal receiving apparatus in synchronism with a corresponding transmitting apparatus in which two definite speeds are allotted to the receiving apparatus one above and the other below true synchronous speed.

- The present invention has for its further object to enable the secondly mentioned portion of the said problem to be solved, namely the reproduction of distorted signals in their originally transmitted form, by the aid of the constantly moving member of telegraph receiving apparatus moving in s vnchronism and correct phase relationship with the corresponding member of the associated telegraphic transmitting apparatus. members may, as heretofore usual, conven- These received signal in the shortest possible space I of time, and reproduce the signal in any required form. In previous constructions of reproducers or regenerators of telegraph signals, it has been the aim to use the middle portion of the received signal, but in all cases a considerable portion, say 30% or 40% of the signal length, has been required for operating the signal reproducing means. This necessitates that at least 30% or 40% of the signal must be readable for the reproducing meansto operate successfully. If the distortion of the signal be so bad that less than this amount of the signal is correct, or if the rotary shaft of the receiver be out of phase with the transmitter shaft so as to reduce the signal that can be read, to less than 30% or 40%, then the signal, may with the said previous constructions, be recorded incorrectly.

For attaining the above mentioned object, telegraphic reproducing apparatus according to the present invention, comprises broadly, s1gnal reproducing means adapted to remain in the position into which it was last moved, independent means adapted to be moved to one or other position in accordance with the polarity of received signals and means adapted to be actuated once in each signalling period to cause the said independent means to act on the signal reproducing means to move it in accordance with the polarity of the received signals.

More specifically considered, the reproduction of each received signal is effected by mechanical means acting in such a manner that the actual reading of the signal is performed during a very short interval of time, that is to say, the time required for two abutting devices, for instance two knife edges, to pass one another.

In the accompanying illustrative drawings, Fig. 1 shows in plan, one construction of telegraphic reproducing apparatus according to the invention, suitable for use when working with the multiple unit code, or with the Morse land line code. Fig. 2 is a developed view showing one form of cam device that can be used. Fig. 3 shows in plan, one construction of telegraphic reproducin apparatus according to the invention, suitable or use when working with the Morse cable code. Fig. 4 is a perspective view showing a detail. Fig. 5 is an end view of part of the apparatus as seen from the plane VV of Fig. 4. Fig. 6 shows in plan and Fig. 7 in section on the line VII-VII of Fig. 6, a modified construction of receiver for a purpose hereinafter described. Fig. 8 shows, diagrammatically, how receivers according to the invention can be used for retransmitting signals over a number of lines.

Fig. 1' may be regarded as an illustration of the principle of the invention, the synchronizing means, not being shown.

, the rotary shaft of the receiver mounted in a bearing 1 and driven in any suitable manner, as through gearing 2 from an electric motor 3 in such manner as to rotate practically .in synchronism with the corresponding shaft of the transmitter 4 is a cam fixed to the shaft A and shaped as is the lefthand cam in Fig. 2,. A lever 5, is mounted on a pivot pin 5, is connected at its free end by a link 6 to an abutment device 7, and 8 is a companion abutment device carried by one arm 9 of a lever pivoted at 9". The other arm 9 of the said lever carries a contact arranged to oscillate between two fixed but adjustable contacts 10 and 11. The movable contact arm 9 is connected say to a telegraph line L over which the received signals are to be correctly reproduced, and the fixed contacts 10 and 11 are connected respectively to the positive and negative poles of a split battery 12, the mid point of which is connected to earth E. The free end portion of the link 6 carrying the abutment device 7 is connected by a link 13, through which it extends, to the armature lever 14 of a polarized power relay 15 responsive tov the incoming signals. The lever 5 is moved by the cam 4 in the middle of each signal period so as to strike the device 7 against the device 8. lVhen say a positive signal is received, the armature lever 14 and link 13 will be moved in the direction of the arrow as and move the freeend of the link 6 and abutment device 7 in the same direction. When say a negative signal is received, the said part-s 14, 13, 6' and 7 will be moved in the opposite direction. The cam disc 4 will suddenly move the abutment device 7 forward in the direction of its length and then move it backwards and this will happen in the middle of each signal period.

Assume the movable contact arm 9a to be bearing against the negative contact 11.

Then when say a positive signal is received by the relay 15, the armature lever 14 will act tomove the abutment device 7 in the direction of the arrow :0 (Fig. 1). I The lever 5 Will act at the middle portion of the signal period to strike the link 6 and abutment device 7 suddenly forward in the direction of the arrow 3 The abutment device will thus act against the lower inclined side of the recess inthe abutment device 8 and move the contact arm 9 from the negative contact 11 against the positive contact 10. A positive signal will thus be transmitted from the battery 12 to the telegraph line L. The said contact arm 9 will remain held firmly in its set position against contact 10, by the jockey ulley 16, for one whole signal period at east, as it cannot be moved by any means except by the striking action of the lever 5. If the polarity of the succeeding signal be the same as the last, say positive, then when the lever 5 performs its next striking movement, the contact arm 9" will not be moved because the abutment device 7 will not have been moved by the relay. If however, the succeeding signal be of opposite polarity, say negative, the abutment device 7 will be moved by the armature lever 14 in the direction of the arrow 00 so that when it is again suddenly struck forward by the lever 5, in the direction of the arrow 3 it will act against the upper inclined side of the recess in the abutment device 8 and move the contact lever 9 against contact 11 and thus transmit a negative signal from the battery 12 to the telegraph line L. It will thus be seen that the duration of each reproduced signal de pends upon the cam-operated movement of the lever 5, but its character or polaritv depends upon the character or polarity of the signal re eived bv the relay 15 at the moment of operation of the said lever.

Figs. 3, 4. and 5 show one construction of reproducer in which the abutment device is moved sideways bv mechanical means under control of the receiving relav instead of directly by the armature of that relav. This reproducer is for reproducing signals according to the Morse cable code. in which separate relays 15 and 15 are provided for responding to positive and negative signals resnectivelv.

On the shaft A is a cam 4 shaped as is the left hand cam in Fig. 2. A lever 5 is adapted to be moved by this cam and forms one arm of a two-armed lever, the other arm 5a having its free end arranged opposite the end of the main shaft 'A and bearing against two bell crank levers 26 and 27. The two armed lever 5, 5A is pivoted at 5a: to a stationary support. The two levers 26 and 27 are connected by a spiral spring 26A. The levers .26 and 27 carry abutment devices 7 and 7 (1. These abutment devices are also attached to rods 37 and 38, which are moved llil and 15a by of each ring 45. At the opposite end of the .tively sleeve 44 is an eccentric 53 on which one end of the corresponding eccentric rod 37 y or 38 is mounted. Each sleeve 44 carries a tooth 47. Two abutments or pallets 48-49 are formed on a bar 13 connected to the armature lever 14 or 14a of the corresponding relay 15 or 15a. The arrangement is such that when one relay say 15, is energized by a positive signal, one of the pallets 48 or 49, say 48, will release the tooth 47 and sleeve 44 and permit the latter, to be rotated from the shaft 39 by the friction ring 45. The tooth 47 is arrested by the other pallet, say 49, when the sleeve 44 has rotated through half a revolution. During such half revolution the sleeve will cause the corresponding eccentric rod, say 37, to move the corresponding abutment device 7 in the direction of the arrow on. Upposite the abutment devices 7a and 7b are other abutment devices 8, 8a carried by levers 9, 9a pivoted at 9:. The levers 9a, 9b carry contact arms 29, 29a movable respectively between contacts 10, 11 and 10a, 11a. The contact arms 29, 29a are connected respecto the line and to earth.

The abutment devices 7 a, 7 b, are moved by -means of the rods 37, 38 in the direction of the arrow :1: or in the opposite direction by the action of the friction clutches under the control of relays 15 and15a. At the middle of the signal period, the abutment devices 7, 7a, will be moved forward by the cam actuated lever 5, 5 and the levers 26 and 27. These abutment devices 7, 7 a' will strike against or miss the corresponding abutment devices 8 or 8a. If no signal is being received neither abutment device 7 or 7 a' will strike its corresponding abutment device 8 or 8a,

- but if say the device 7 has been moved in the direction of the arrow :0, it will when struck by the lever 26 move the contact arm 29 a ainst the contact 10, and a positive signal will be sent to line. At the end of the received signal, the relay armature 14 moves back to its original position and operates the escapement devices in a direction to permit the sleeve 44 and eccentric to make another half revolution and return the eccentric rod 37 and abutment device 7 to their original positions. When the other relay 15a is oper ated by a negative signal, similar actions take place to those just described, to actuate the abutment devices 712, 8a and contact operating lever 9a. The arrangement is such that when the contact blade 9 is moved sideways from its normal position against the positive contact 10, by the co-actin abutment devices 7 and 8 on the receipt of a positive signal, it will act to connect the positive poleof the battery 36 to line L while the negative pole of the said battery is connected to earth, and when the other contact blade 29a is moved against .the positive contact 10a by the coacting abutment devices 7a and 8a on the receipt of a negative signal, the connections of the battery to line and earth will be respaced.

This is carried out by means of a returning rod 53 operated from another lever 54 controlled from the same cam on the shaft A and provided with an abutment 55 adapted to act on additional arms 29?) fixed to the levers 9 and 9a respectively.

The same friction clutches and escapement devices are used for'causing the striking movements of an abutment device 58 against an abutment device 59 carried by a contact lever 60, used for bringing into action alternately, one or other of two governors for controlling the speed of the motor used for driving the main shaft A.

Two levers 6.3 and 64 pivoted at 63 and 64 are operated by cam grooves 65 and 66 respectively in the two rotary sleeves 44 and caused to strike an abutment device 58 towards the abutment device 59 at each response of relays 15 and 15a to received signals. Also, a lever 67 for moving the abutment device 58 transversely to the abutment device 59 before it is struck forward for receiving signals and accurately reproducing such signals, can be effected.

The reproduced signals may, instead of being retransmitted to another line or station as hereinbefore described, may be used in any known or suitable way to operate signal recording means, for instance for operating mechanism for reproducing the signals in the form of perforations in a tape, or it may be in ink form on a ribbon, as may be required, or, as in multiplex practice, for operating printers direct, or by the aid of a cur rent distributor.

The operative movements of the striking abutment 7 or 7 a, may be used to perforate directly a paper tape, suitable punches, dies and feed mechanism being provided.

' duplex and two receivers are used at each station, the receiver for retransmitting signals in one direction may be constructed with means for synchronizingit with the corresponding transmitter, but the receiver for retransmitting signals in the opposite direction may utilize the same driving means as the first mentioned receiver. The relative position of the cam thereon used for controlling :the retransmission of si nals in the reverse direction will then be adjusted so that it will be in the correct phase relationship with the received signals. In this way, the use of separate means for causing the shaft A of the receiver to run in synchronism and correct phase relationship can be avoided.

A mean-s for adjusting the cam for actuating the striking means for reproducing the signals is of utility in connection with any receiver. Figs. 6 and 7 show a receiver adapted for use with the multiple unit code or the Morse land line code with cam 68 for moving an abutment device 58 to indicate the phase of the shaft for synchronizing purposes and a cam 4 to strike forward an abutment device 7 for reproducing purposes. The striking action of the cam 4 is performed through the agency of a two armed lever 5, 5A, the arm 5 of which is moved by the cam 4 and the arm 5A of which strikes forward the abutment device '7. The end of the lever 5 moved by the cam 4 is shown in the Figuresti and 7 as exactly opposite the end of the lever 67 moved by the cam 68. The effect of an adjustment of the relative positions of the cams is obtained by adjusting the position of the two armed lever 5, 5A. To this end this lever is pivoted to a spindle 5m in an arm 95 carried by a segment 96. The segment 96 is coaxial with the shaft A and normally fixed in position. It may be adjustedthroiigh an angle of 90 by means of a worm 98 on a spindle 99 which may be rotated by a knurled knob 100.

A similar construction of adjusting means for the purpose mentioned, is shown in the receiver designed for cable code working shown in Figs. 3 and 5.

Fig. 8 shows diagrammatically the arrangement of a telegraph system arranged for diiferential duplex working according to the multiple unit or the Morse land line code. The system has two terminal stations 1 and 2 and an intermediate station 3, though it will be clear that any number of intermediate stations may be used.

At the station 1, I represents the signal transmitter connected in Well known manner means subsequently nal period to cause the said independent to the middle point of the windings of the transmitting tongue for retransmitting to.

station 2 and is thus connected to the mid point of relay G connected'to artificial line L and line L leading to station 2.

Thetransmitter I and receiving relay F at station 2 are. connected in the same way as transmitter T and relay E at station 1. Signals sent from station 2 to relay G of receiver D at station 3 are retransmitted by the reproducing lever K of receiver D to sta- 1 tion 1.

The reproducing levers S and S at stations 1 and 2 are connected to recording means T and T respectively, which may be printing telegraph receivers.

The shaft B of station 1 is caused to run at a constant speed in any convenient manner. The receivers O and D at station 3 are driven from the same shaft A, driven by a motor which is given either of two definite speeds. The speed is changed from one to the other when required under control of an indication of the phase of the shaft A and signals received by relay G. The shaft A at station 2 is also driven by a motor which may have either of two definitespeeds, the speed being allotted under control of signals received by relay F from reproducing lever M of station 2.

It will be understood that the .above described system makes use of the difi'erential duplex method of working, but it will be obvious that the bridge duplex method of working could be used if deslred and would preferably be used in the case of cable code working. 1

The'details of construction of apparatus according to the invention can be variously modified without departing from the essential features of such apparatus.

What is claimed is: Y

1. Telegraphic reproducing apparatus comprising signal reproducing means adapted to remain in theposition into which it was last moved, independent means positioned in accordance with received signals, and

acting once in each sigmeans to act on the signal reproducing means.

2. Telegraphic reproducing apparatus comprising contact making means having two positions, means for retaining it in either position, signal responsive means capable. of occupying two positions out of engagement with said contact making means, and periodic means for bringing said signal responsive means into operable relation with said contact making means.

3. Telegraphic reproducing apparatus comprising signal reproducin means, signal responsive means, and mec anical means for actuating said signal reproducing means according to the position of said signal responsive means at the middle of each signal period.

4. Telegraphic reproducing apparatus comprising a rotating shaft, means for sychronizing the speed of the shaft, a cam on said shaft, signal responsive means, signal reproducing means, and means operable by saidcam at the middle of each signal period for momentarily bringing said signal responsive means into operable relation with said signal reproducing means, and means for retaining said signal reproducing means in the position thus taken.

5. Telegraphic reproducing apparatus comprising a pivoted lever moveable into either of two positions and having a firstknife edge thereon, a second knife edge having its axis in line with that of the first knife edge, a signal responsive relay means under the control of said relay for moving the said second knife edge at right angles to its axis and means for periodically moving the said second knife edge in the direction of its axis and against the said first knife edge to move the said pivoted lever into one or other position according as the said second knife edge is on one or other side of the axis of said knife edges, means for reproducing one or other signal according to the position of said pivoted lever, and means for retaining said pivoted lever in the position last taken.

6. In telegraphic reproducing apparatus the combination of a rotating shaft, means for synchronizing said shaft, a first cam driven by said shaft to actuate phase indicating means, signal responsive means, means under the control of said signal responsive means for rendering said phase indicating means operative on said means for synchronizing and for moving a signal indicating means, a second cam driven by said shaft and means operable by said second cam momentarily to bring said signal indicating means into operativerelation with signal reproducing means, and means for retaining said signal reproducing means in the condition thus brought about. 1

' 7. The combination accordingto claim 6, together with means for adjustingthe time of operation of said signal indicating means on said signal reproducing means in relation to the time of operation of said phase indicating means on said means for synchroniz- Telegraphic reproducing apparatus comprising means responsive to positive signals, means responsive to negative signals, signal reproducing means, and means actuated at the middle of each signalling period to cause either of the signal responsive means to actuate momentarily the saidsignal reproducing means in the appropriate manner and means for retaining the signal reproducing means in the condition thus brought about for a full signal period, and means for thereupon returning said signal reproducing means into normal position.

9. Telegraphic reproducing comprising slgnal reproducing means adapted to remain in the position into which it was last moved, independent means moved in one dlrection in accordance with received signals, and means acting once in each signal period to cause the said independent means to move in a second direction to act on the signal reproducing means.

10. Telegraphic reproducing apparatus comprising signal reproducing means, signal responsive means, and mechanical means for actuating said signal reproducing means through said signal responsive means at the middle of each signal period.

11. In a telegraph system and in combination, a changeover member operable from one position to another to effect changeover, one end of said member terminating in an angular abutment, a second member laterally movable relative to said changeover member and having an angular abutment for engaging the abutment of the changeover member, means for laterally moving the second member, and means for periodically reciprocating one of said members to cause said angular abutment to engage and thus register the instantaneous lateral position of said second member upon the changeover member.

12. In a telegraph system and in combination, a changeover member operable from one position to another to effect changeover, one end of said member terminating in an angular abutment, a second member laterally movable relative to said changeover member and having an angular abutment for engaging the abutment of the changeover member, means for laterally moving the secondmember, and means for periodically reciprocating said second member to cause said angular abutments to engage and thus register the instantaneous lateral position of said second member upon the changeover member.

13. The method of maintaining corresponding controllingand controlled apparatus in synchronism which comprises driving the controlling apparatus at a constant speed, allotting two speeds to the controlled apparatus one above and one below true synchronous speed and mechanically changing the speed of the controlled apparatus from on to the other as and when required.

14. The method of maintaining in synchronism controlling and controlled apparatus, which are intended to perform corresponding cycles of operation, which consists in driving the controlling apparatus at a constant speed, allotting two speeds to the controlled apparatus, one above and one below true synchroapparatus nous speed, and in mechanically choosing from time to time one of said speeds in ac-' cordance with a combined indication of the phase of the. controlling apparatus and the phase of the controlled apparatus.

15. In combination a controlling apparatus and a controlled apparatus each adapted to perform a continuous cycle of operations, means for driving the controlling apparatus at a predeterminedspeed, means for driving the controlled apparatus, means for determining that the speed of the said controlled apparatus shallbe above the said speed of the controlling apparatus by a predetermined amount, means for determining that the speed of the said controlled apparatus shall be below the speed of the controlling apparatus by a predetermined amount, means for indicating the position of the controlled apparatus in its cycle of operations relative to the position of said controlling apparatus. and mechanical means for choosing one or other of said speed determining means.

16. In combination a controlling apparatus and a controlled apparatus each adapted to perform a continuous cycle of operations, means for driving the controllin apparatus at a predetermined speed, means for driving the controlled apparatus, means for determining that the speed of the said controlled apparatus shall be above the said speed of the controlling apparatus by a predetermined amount, means for determining that the speed of the said controlled apparatus shall be below the speed of the controlling apparatus by a predetermined amount, means for,

indicating the position of the controlled apparatus in its cycle of operations relative to the position of said controlling apparatus and mechanical means operatively associated with said speed indicating means choosing one or other of said speed determining means.

17 In combination, a controlling apparatus and a controlled apparatus each adapted to perform a continuous cycle of operations, means for driving the controlling apparatus at a predetermined speed, means for driving the controlled apparatus, means for setting the speed of the controlled apparatus at either of two definite speeds one above and onebelow true synchronous speed, means for send ing signals from said controlling apparatus indicative of the phase thereof to said con trolled apparatus, means at said controlled apparatus for indicating the phase thereof, and mechanical means automatically respon sive to the combined effect of said signals and said indicating means to set the speed at one or other of said definite speeds.

18. In a synchronous telegraph system the combination of a receiving apparatus adapted for continuous rotation, means for setting the speed of said apparatus at one or other of two definite speeds, mechanical means for indicating the phase of said apparatus, means for receiving signals, and means responsive to .said last mentioned means and said phase indicating means to operate said speed setting means. 1

19. In a synchronous telegraph system the combination of a rotating shaft, means for setting the speed of said shaft to be either of two definite speeds means for receiving signals, means responslve to said signals for recording a message represented by them, means for indicating the phase of said shaft, mechanical means responsive to said signals and said phase indicating means to operate said speed setting means.

20. In synchronous telegraph repeating apparatus the combination of a rotating shaft, means for setting the speed of said shaft to be either of two definite speeds, means for receiving signals, means responsive to said signals for retransmitting signals representing the said signals, mechanical means for indicating the phase of said shaft, means responsive to said first mentioned signals and said phase indicating means to operate said speed setting means.

21. In a synchronous telegraph system a rotating shaft, means for setting the speed of said shaft to be either of two definite speeds, means for receiving signals, means for indicating a particular condition of said signals, mechanical means for indicating the phase of said shaft, and automatic means operative at the moment of indication of said signals to operate said speed setting means in accordance with said phase.

22. In a synchronous telegraph system a rotating shaft, means for setting the speed of said shaft to be either of two definite speeds, a line, signal receiving means connected to said line and responsive to change of signalling conditions therein, mechanical means for indicating the phase of said shaft and means operable by said signal receiving means each time said change of signalling conditions occurs to operate-said speed setting means in accordance with said phase.

23. In a synchronous telegraph system a rotating shaft at a transmitting station, a rotating shaft at a receiving station, and indicating means mechanically operated from said last mentioned shaft adapted to indicate a lag or a lead in phase with respect to said first mentioned shaft. and speed correcting means operated by said indicating means.

24;. In a synchronous telegraph svstem a rotating shaft, a first member moved in a continuous manner by said shaft, and a phase indicating member moved by said first member only at certain phases of rotation of said shaft.

25. In a synchronous telegraph system a rotating shaft, a sine shaped cam for said shaft. a first lever, a roller attached to said first lever and moved by said cam, a second lever and means for moving said second lever as i only when said roller is moved by the steepest portions of said cam.

26. In a synchronous telegraph system, a rotating shaft, a member carrying a first knife edge a pivoted lever carrying a second knife edge having its axis substantially parallel to that of the first knife edge, means for moving from time to time the member towards the lever to determine the direction of rotation of the said pivoted lever, and means for setting the speed of said shaft in accordance with said direction of rotation.

27. In a synchronous telegraph system, a

rotating shaft, a line, a first signal responsive means connected to said line and responsive only to one kind of signals from said line, a second slgnal responsive means connected to said line and responsive only to another kind of signals from said line, indicating means for indicating the phase of said shaft, means for setting the speed of said shaft at one or the other of two definite speeds, means actuated by each of said signal responsive means to operate the last mentioned means in accordance with said indicating means. In witness whereof, we hereunto subscribe our names this seventh day of December, 1928.

FREDERICK GEORGE CREED. REGINALD DENNIS SALMON. 

